Now comes a profoundly learned and widely honored man, demanding that humankind regroup all knowledge and reroute all learning. The shock: He is stark sane. The man is Edward O. Wilson. His demand is summed up in a wonderful new book, "Consilience: The Unity of Knowledge" (Knopf, 352 pages, $26).

You should know who he is. An Alabaman, now 69, Wilson has been teaching for 43 years at Harvard, where he got his Ph.D. in biology. Two of his six previous books won Pulitzer Prizes: "On Human Nature," and "The Ants.".

From his scholarly beginnings as an ant biologist - he is undisputed emperor of the field - and a great deal of study in jungles and elsewhere, Wilson became one of the earliest influential enthusiasts for "biodiversity," preservation of every possible life form on Earth - a term he invented or at the very least hammered into the language.

His 1984 book, "Biophilia: The Human Bond With Other Species," remains the classic in the field. No sentimentalist, his arguments are deeply practical, standing on the demonstrable interdependence and fragility of human and other life. He has a more legitimate claim to the titles "environmentalist" and "ecologist" than any person alive today, and arguably all those dead as well.

His battle cry is not a coined word. He chooses to use "consilience" because although its meaning is not far from "coherence" that latter term has been muddied in meaning.

Cause and effect

By consilience he means the joining, drawing together of all fields of knowledge: "The deliberate, systematic linkage of cause and effects across the disciplines."

He insists that science and the social sciences and the humanities, and even the arts and their interpretation, must be married - or remarried, after a long, ugly divorce - as one broad matter, as a core of knowledge. Otherwise, he argues, none of the elements will grow healthily, and all will continue to deteriorate in isolation. "Science needs the intuition and metaphorical power of the arts, and the arts need the fresh blood of science."

How to do it? First, through thoughtful, courageous and creative decisions by intellectual and scholarly leaders, and then through a major reordering of the education system's structure and priorities.

His core point - consilience itself - is what until surprisingly recently was considered the backbone of civilization by most literate people in the Western, and much of the Eastern, world.

"During the past 30 years," he writes, "the ideal of the unity of learning, which the Renaissance and Enlightenment bequeathed us, has been largely abandoned. With rare exceptions, American universities and colleges have dissolved their curriculum into a slurry of minor disciplines and specialized courses. While the average number of undergraduate courses per institution doubled, the percentage of mandatory courses in general education dropped by more than half."

His language is clear and energetic, often brilliant and amusing at once: Take his chastising definition of "-ism"s: "the hissing suffix." There are few passages of more than three or four pages that do not contain some insight or phrase that asks to be written down as one reads.

So tight and intricate is the fabric of the entire book, it is perilous to offer specially representative gems. But I do like this: "Even Winston Churchill, whose country was saved by radar, worried after the atom bombing of Japan that the stone age might return 'on the gleaming wings of science'." And this: "The ideal scientist thinks like a poet and works like a bookkeeper, and I suppose that if gifted with a full quiver, he also writes like a journalist."

His case leans heavily on the Frankenstein metaphor. Technology without wisdom is life's great enemy; isolated specialization inevitably leads to intellectual blindness - or severe myopia - and thus to deterioration of culture and loss of moral context.

"To others concerned with the growing dissolution and irrelevance of the intelligensia, which is indeed alarming," he writes, "I suggest there are and have always been two kinds of original thinkers, those who upon viewing disorder try to create order, and those who upon encountering order try to test it by creating disorder. The tension between the two is what drives learning forward."

Know nothings

"Enlightenment thinkers believe we can know everything," he writes at another point, "and radical postmodernists believe we can know nothing."

Wilson's examination of the theories of Jacques Derrida, the creator of deconstruction, Michel Foucault and others of their academic tribe is set in the context of a tour de force of cultural history and appreciation. Wilson's comprehension of the sweep of philosophical, artistic and scientific history gives prodigious authority to his dismissal of these self-styled postmodernists..

While Wilson offers the kindest possible personal view of those savagely anti-intellectual Vandals and Visigoths who now dominate much of the American academy, he is unforgiving of their failings that he dissects. His fairness strengthens his case.

In 1975, Wilson's book "Sociobiology: The New Synthesis" was published, to the violent reaction of the immediate ancestors of today's Political Korrectness Kops. That volume later was voted by a prestigious international learned society to be the "most influential book" in the 20th century. Such are the costs - and too occasional rewards - of intellectual integrity

This new book is a work to be held in awe, to be read with joy and attentiveness, to be celebrated and challenged and returned to again and again. It is, in short, an act of consummate intellectual heroism.